1. Field of the Invention
This invention relates to a device for use in the endodontic surgery which is one of the methods for the treatment of diseases of a dental root. More particularly, it is concerned with a dental root marking and measuring instrument for marking the position of a dental root externally and measuring the thickness of a bone.
2. Description of the Prior Art
Endodontic surgery is believed to be a suitable method for the treatment of diseases of a dental root which are difficult to treat through a pulp canal. In order to carry out a surgical operation, however, it is necessary to ascertain the position of a dental root from the exterior. This has hitherto been done by ocular inspection, palpation and intuition of the operator with the aid of an X-ray picture and the findings on the swelling or color of the alveolar bone. If the alveolar bone at the dental root is broken, it is relatively easy to ascertain the position of the dental root. In the event no broken portion of the bone can be easily found with the naked eye, it is sometimes effective to prick strongly with a probe several portions of the alveolar bone which appear to be broken, since the probe can be pierced through any thin bone portion covering the site of a disease. If it is still impossible to locate any broken portion, or if no image of X-ray transmission is observed, it has been usual to dispose a reamer used for measuring the length of a pulp canal along the alveolar bone facing the lip by taking the direction of the dental root into consideration, and assume the position of the dental root from the position of the end of the reamer. In the event even this method is ineffective, an X-ray picture is taken with an X-ray-impermeable object, such as a lead foil or ball, or a small ball of a gold foil, placed in a removed portion of the bone, and the positional relationship between the dental root and the X-ray-impermeable object is examined, whereby the position of the dental root is assumed. All of these methods, however, require a lot of time and labor. It is difficult to determine the position of a dental root correctly, and there is every possibility of making a mistake in locating it. Accordingly, there is every likelihood of the healthy bone being unnecessarily removed, or a normal dental root being damaged.